NAMBA strut question

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Matt Smith

Well-Known Member
Joined
Sep 11, 2011
Messages
254
Just a quick question regarding extended struts on 1/8th scales. The NAMBA rule states the drive dog can extend one drive dog length past the transom.

How does this work for modern unlimiteds with extended struts well past the transom?
 
I'll try to get some info about this off the "Miss Dreamliner" tomorrow since I'll be working only a few miles from the HARM. Since the rules, specifically 21.C.9, gives you a drive dog spacing(roughly 1/4 to 3/8 of an inch, depending on the drive dog) from the transom to the front of the prop, that may be very close to the distance from the rear of the hull to the front of the prop
 
I would say if you can document the extended strut you'll be OK. Outdrives are illegal or need to be documented when used. OMHO
Thats what the IMPBA rule says. The NAMBA rule isnt clear in my opinion. As it stands now, the drive dog is 1'' behind the transom, and the front of the prop is 1-1/4" on my 2002 Bud, which I have documentation that shows the strut as extended on the real boat.
 
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I would say if you can document the extended strut you'll be OK. Outdrives are illegal or need to be documented when used. OMHO
Thats what the IMPBA rule says. The NAMBA rule isnt clear in my opinion. As it stands now, the drive dog is 1'' behind the transom, and the front of the prop is 1-1/4" on my 2002 Bud, which I have documentation that shows the strut as extended on the real boat.
Kevin Traboulay is class chairman try contacting. [email protected]
 
An inch past the transom sounds kind of long, considering that's a full 8" in full sized boat. IIRC, the full sized boats only have around 2-3" between the strut and the front of the prop. As I said, I'll do some checking and get back to you later today
 
Matt I have mine 1 drive dog length past the transom. I think that's all you really need.
I would agree. I get that my strut is probably longer than it needs to be, but there is gray area in the IMPBA rules as well. If the real boat has an extended strut, then you can run it on your scale. It doesnt give a limit to length.
 
Matt I have mine 1 drive dog length past the transom. I think that's all you really need.
I would agree. I get that my strut is probably longer than it needs to be, but there is gray area in the IMPBA rules as well. If the real boat has an extended strut, then you can run it on your scale. It doesnt give a limit to length.
I have an extended strut on mine. The very back part of the strut is at the very back part of the transom on mine. Leaves a Drive sticking out. I've talked to several several people in Scale in IMPBA and that's pretty much the standard length from the transom on winged boats. I think any farther is way too much.
 
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Matt I have mine 1 drive dog length past the transom. I think that's all you really need.
I would agree. I get that my strut is probably longer than it needs to be, but there is gray area in the IMPBA rules as well. If the real boat has an extended strut, then you can run it on your scale. It doesnt give a limit to length.
I have an extended strut on mine. The very back part of the strut is at the very back part of the transom on mine. Leaves a Drive sticking out. I've talked to several several people in Scale in IMPBA and that's pretty much the standard length from the transom on winged boats. I think any farther is way too much.
Agreed, but again there is no clarity on the rule in either organization. The way IMPBA states the rule, you could run the prop 3 inches behind the transom if you wanted to. While not smart, you technically could.
 
Matt I have mine 1 drive dog length past the transom. I think that's all you really need.
I would agree. I get that my strut is probably longer than it needs to be, but there is gray area in the IMPBA rules as well. If the real boat has an extended strut, then you can run it on your scale. It doesnt give a limit to length.
I have an extended strut on mine. The very back part of the strut is at the very back part of the transom on mine. Leaves a Drive sticking out. I've talked to several several people in Scale in IMPBA and that's pretty much the standard length from the transom on winged boats. I think any farther is way too much.
Agreed, but again there is no clarity on the rule in either organization. The way IMPBA states the rule, you could run the prop 3 inches behind the transom if you wanted to. While not smart, you technically could.
Matt,

I don't know where your getting the prop 3" behind the transom allowed in IMPBA

The rule states Drive dog must not extend beyond the transom unless the prototypes strut and/or drive dog did so. Still kinda sketchy to me. what REAL boat uses a drive dog?
 
Matt I have mine 1 drive dog length past the transom. I think that's all you really need.
I would agree. I get that my strut is probably longer than it needs to be, but there is gray area in the IMPBA rules as well. If the real boat has an extended strut, then you can run it on your scale. It doesnt give a limit to length.
I have an extended strut on mine. The very back part of the strut is at the very back part of the transom on mine. Leaves a Drive sticking out. I've talked to several several people in Scale in IMPBA and that's pretty much the standard length from the transom on winged boats. I think any farther is way too much.
Agreed, but again there is no clarity on the rule in either organization. The way IMPBA states the rule, you could run the prop 3 inches behind the transom if you wanted to. While not smart, you technically could.
Matt,

I don't know where your getting the prop 3" behind the transom allowed in IMPBA

The rule states Drive dog must not extend beyond the transom unless the prototypes strut and/or drive dog did so. Still kinda sketchy to me. what REAL boat uses a drive dog?
I was using it as an example. The rule says you can run an extended strut as long as you can prove the real hull ran one. There is no length limit.
 
Maybe there should be a length rule for that. Maybe a max of say

" Drive dog can't be past the transom no more then 1". "

But I do get what your saying.

I know some guys around my area about the changes that where made to the 1/8th Scale rules about what boats can and can't run. Buts that's a whole nother topic.
 
Seems NAMBA's rule is clear.

[SIZE=12pt]The propeller drive dog may extend one drive dog length beyond the transom.[/SIZE]



Not sure how that isn't clear. Does not give allowance for newer or older boats. It does give allowance for outdrives, articulating shafts, sponson pads, rudder and turn fins. But drive dog location is very clear.

It may be something that needs updating but..........
 
Seems NAMBA's rule is clear.

The propeller drive dog may extend one drive dog length beyond the transom.

The NAMBA rule is definitely more clear.

Not sure how that isn't clear. Does not give allowance for newer or older boats. It does give allowance for outdrives, articulating shafts, sponson pads, rudder and turn fins. But drive dog location is very clear.

It may be something that needs updating but..........[/quote

The NAMBA rule is more clear, but neither one is completely accurate.
 
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Matt consult your District scale director or Give Joe a call
I am the scale director for D1 buddy
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When I raced in Seattle I always made sure my drive dog was less then a length from the transom. NorthWest and RCU guys make it work just fine
 
Seems NAMBA's rule is clear.

[SIZE=12pt]The propeller drive dog may extend one drive dog length beyond the transom.[/SIZE]



Not sure how that isn't clear. Does not give allowance for newer or older boats. It does give allowance for outdrives, articulating shafts, sponson pads, rudder and turn fins. But drive dog location is very clear.

It may be something that needs updating but..........
Hey Robert,

I just started a new business. Custom drive dogs. How long would you like yours? LOL Using a standard length for drive dog, then it would be 1/2 inch. I have a lathe and a mill. Should be able to whip out some 1" long ones to be in the gray area of that rule. Heck how about 2". Would need to build some shafts then.
 
Seems NAMBA's rule is clear.

The propeller drive dog may extend one drive dog length beyond the transom.

Not sure how that isn't clear. Does not give allowance for newer or older boats. It does give allowance for outdrives, articulating shafts, sponson pads, rudder and turn fins. But drive dog location is very clear.

It may be something that needs updating but..........
Hey Robert, I just started a new business. Custom drive dogs. How long would you like yours? LOL Using a standard length for drive dog, then it would be 1/2 inch. I have a lathe and a mill. Should be able to whip out some 1" long ones to be in the gray area of that rule. Heck how about 2". Would need to build some shafts then.
My point exactly! This would be legal for both sanctions!
 
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